Experimental Study On The Mechanics Of The Enhanced Heat Transfer In A Plate Heat Exchanger With Compound Corrugation Flow Channels

Plate heat exchanger is a kind of heat exchanger with high heat transfer coefficient and low heat loss which is easy to clean, not easy to scale.However, large flow resistance, uneven flow distribution and other issues also affect its comprehensive performance to further improve. Therefore, scholars have carried out widespread exploration on the plate heat exchanger and made some progress. But as a new form of heat exchanger, scholars have less research on plate heat exchanger with compound corrugation flow channels.At the same time, the former experimental study on the flow state of plate heat exchanger was mostly qualitative observation and analysis. So the error was larger, and the flow parameters such as velocity and vorticity cannot be obtained accurately, which reduces the reliability and comprehensiveness of the experimental results. The flow path of plate heat exchanger was relatively narrow, which also limited the feasibility of contact measurement and increased the difficulty for its further study.In order to solve the problems above, PIV technology was used to study on the plate heat exchanger with compound corrugation flow channels based on previous studies in this paper. And the numerical calculation was carried out under the LES model, which was compared to the experimental results.The main work and conclusions were as followed:(1) The PIV experiment was carried out on XY section of the plate heat exchanger with compound corrugation flow channels. A circulating waterway system and a two-dimensional PIV test system were designed and set up. The organic plate experimental model with single flow path of the composite channel with corrugation angle of 25° and 55° was made. Four heat transfer area and three flow images were collected, 80000 flow parameters ware got after calculation. Streamline and speed cloud were draw out with Tecplot software, the law of biased flow phenomenon, flow state and heat transfer effect etc. were found.(2) The PIV experiment was carried out on XZ section of the plate heat exchanger with compound corrugation flow channels. A circulating waterway system and a two-dimensional PIV test system were designed and set up. The ultra-white glass experimental model with single flow path of the composite channel with corrugation angle of 25 ° and 55 ° was made. The images of four heat transfer area were collected and 24000 flow parameters were got after calculation. Streamline and speed cloud were draw out with Tecplot software,the flow pattern and heat transfer characteristics of the section are analyzed and obtained.(3) The flow field visualization experiment of the plate heat exchanger with compound corrugation flow channels was carried out. The experimental system and model was designed and made, and the experimental parts were set up. The tracer was injected and the flow field was recorded in a steady state.As a result, the characteristics of the deviation of the whole flow field, the blending state and the velocity distribution etc. were found.(4) The simulation calculation of the plate heat exchanger with compound corrugation flow channels was completed. A geometric model consistent with the experimental model size and structure was constructed. The grid was divided and the boundary condition was set to fit the model. The LES method was used to calculate the whole flow parameters under the theoretical flow velocity at 0.5 m/s, and the results were compared to experiments.